The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
With the development of conventional communication networks, Internet and mobile communication networks, it is an inevitable tendency for various networks to merge with each other. The Next Generation Network (NGN) is a new generation network merging various networks, in which the Internet Protocol (IP) packet switched network serves as the core network, the control and bearer are separated and various access techniques coexist, so as to satisfy demands of future broadband multimedia communications.
The NGN bears all the services of the existing Public Switched Telephone Network (PSTN), meanwhile unloads a great deal of data transport to an IP network so as to reduce the load of the PSTN, and increase and enhance, based on new characteristics of IP technology, many new and old services. The NGN is developed based on the merging of various networks such as the Time Division Multiplexing PSTN voice network, Integrated Services Digital Network (ISDN), IP-based packet network, mobile communication network, and etc. The NGN makes it possible to implement integrated services, such as voice, video, data and the like, in new generation networks.
The NGN is defined by the International Telecommunication Union (ITU) as a packet based network capable of providing telecom services for users and providing various broadband and Quality of Service (QoS) guarantee, wherein service related functions are independent of transport related bottom-layer techniques. The NGN enables a user to freely access networks, competing service providers and services chosen by the providers, and supports general mobility such that the user may receive consistent and common service provision.
Basic characteristics of the NGN include: packet-based transfer; control function separation between bearer ability, call/session and application/service; decoupling of service provision and transport, and providing open interfaces; based on service construction block (including real-time/stream/non-real-time services and multimedia) to support wide-area services, applications and mechanisms; end-to-end QoS and transparent broadband ability; interacting with conventional networks through the open interfaces; universal mobility; free access for a user to different service providers; diversified identification scheme that may be resolved to an IP address to route in an IP network; sensing by the user that one service possesses uniform service characteristics; merging services between fixed and mobile networks; service-related functions independent of bottom-layer transport techniques; supporting various last mile techniques; adapted to all control requirements, such as urgent communications, security/privacy, and etc.
FIG. 1 is a logic block diagram illustrating the architecture of an NGN system. As shown in FIG. 1, the NGN includes a Network Attachment Subsystem, a Resource and Admission Control Subsystem (RACS), a PSTN/ISDN Emulation Subsystem, an IP Multimedia Subsystem (IMS), a Streaming Services Subsystem and other Multimedia Subsystem.
The IP bearer network includes a Core Transport Network and an Access Transport Network. A terminal accesses the IP bearer network through an Access Function; different IP transport networks interconnect with each other through an Edge Function, for example, between the Access Transport Network and the Core Transport Network, or between different domains of the Core Transport Network; and the Core Transport Network interconnects, through a gateway, with other networks such as a conventional fixed or mobile network.
The RACS is in charge of uniform management of bearer network resources. The RACS includes a Policy Decision Function Entity (PDFE) for arbitrating, based on the status of network resources and a preset control policy, a service decision on security, resources, media and the like related to IP network interconnecting. It further includes a Transport Resource Control Function Entity (TRCFE) for managing the IP network resources of itself.
Because of demands of user service transport, it is necessary to interconnect between different IP networks, e.g., between the Access Transport Network and the Core Transport Network, or between different domains of the Core Transport Network. Therefore, a function entity located in an interconnecting node, namely Border Gateway Function Entity/Packet Gateway Function Entity (BGFE/PGFE), may also include such functions as security protection, resource guarantee, and media processing. However, when a Border Gateway Control Function Entity/Packet Gateway Control Function Entity (BGCFE/PGCFE) initiates a request for IP network interconnecting services, there has been so far no definite and effective method and system for controlling the BGFE/PGFE according to the status of network resources and the policy of the operator to implement network interconnecting.
The inventor of the present invention found in the inventing process that, with further evolvement of the NGN and emergence of various related standards, how to solve the problem of effective border/packet gateway control has become one of the key techniques for developing the NGN. However, no technical schemes can effectively solve the problem at present, that is to say, it is yet impossible to control the BGFE/PGFE in various aspects according to the status of network resources and the policy of the operator so as to implement network interconnecting. As a result, further development and evolvement of the NGN is severely hampered.